(i) Technical Field
The present invention relates to an image forming apparatus.
(ii) Related Art
There has been known an image forming apparatus that performs printing by writing an image on a photoconductor through exposure of the photoconductor, attaching toner to the photoconductor along the image, transferring the attached toner onto a printing medium such as paper, and fixing the transferred toner on the printing medium.
As an exposure method for a photoconductor, there have been known a laser raster output scanner (ROS) method that scans light emitted from a laser light source by using a polygonal mirror and a method using a light emitting element unit including light emitting elements serving as a light source. As the method using the light emitting element unit as the light source, an LED print head method using light emitting diodes (LEDs) as the light source is known.
In the LED print head method, an LED print head including plural LEDs arranged in one direction is used. The LED print head is disposed at a position closely opposed to a photoconductor so that light emitted from the plural LEDs is focused on a surface of the photoconductor in a printing operation. At that position, the plural LEDs emit light toward the photoconductor to expose the photoconductor.
A photoconductor is a consumable member that needs to be periodically replaced. A typical photoconductor is combined with a charging unit for charging the photoconductor and a cleaning unit for removing residual toner on the photoconductor so as to constitute a photoconductor unit. It is general to replace the whole photoconductor unit. Further, a process unit is sometimes constituted by the photoconductor unit and a developing section (a combination of a developing unit for attaching toner to an image formed on the photoconductor and a toner supply unit for supplying toner to the developing unit), and the whole process unit is replaced.
As described above, since the LED print head is disposed at the position close to the photoconductor during a printing operation, it needs to be moved to a position apart from the photoconductor or the photoconductor unit so as not to interfere with the photoconductor or the photoconductor unit during replacement of the photoconductor.